This document summarizes a study that evaluated the outcomes of oral implants placed in bone with limited bucco-oral dimensions over a 3-year period. 100 implants were placed in 28 patients. The study found that the implants had a 100% survival rate over 3 years and that the marginal bone levels around the implants remained stable. The results indicate that implants can successfully be placed in sites with up to 4.5mm of bucco-oral bone width without the need for bone grafting, providing patients maintain good oral hygiene.
2. THE OUTCOME OF ORAL IMPLANTS
PLACED IN BONE WITH LIMITED
BUCCO-ORAL DIMENSIONS: A 3-YEAR
FOLLOW-UP STUDY
Temmerman A et al.
J Clin Periodontol 2015
Shilpa Shivanand
II MDS
3. Introduction
• The clinical success of an implant partially depends on several
external factors primary implant stability, bone quality,
time of loading, infection control, surgical technique and
height and width of the alveolar bone.
• Primary implant stability is determined by the properties of
the bone that contribute to its strength.
• Implant micro-movements within a range of 50–150 μm
seem to be acceptable for optimal bone healing
Szmukler-Moncler et al 1998
4. 4
Parts Of A Dental Implant
IMPLANT BODY
COLLAR
ABUTMENT SCREW
FIXATION SCREW
LAB ANALOGUE
7. • Inter-arch space:
For fixed implant-supported
prosthesis:
7 mm - in the posterior region
8-10 mm - in the anterior areas.
An implant-retained removable
prosthesis requires at least 12
mm.
8-10mm
12 mm
7mm
8. Adjacent teeth:
• At least 7 mm between two
adjacent teeth.
• Adjacent teeth must be
infection free:
all restorative, periodontal,
and endodontic procedures
should be completed prior to
implant planning.
7 mm
7 mm
9. • The defining factors for bone quality are trabecular thickness,
mineral density and micro-architecture
Ribeiro-Rotta et al 2007
• In relation to time of loading, a recent review showed no
differences in marginal bone level changes between different
loading protocols
Suarez et al 2013
• However, the length of the implant seems of interest for the
survival rate of most implant systems.
10. • Since implant survival decreases when the implant is shorter
than 7 mm
Pommer et al 2011
• To determine the health of the peri-implant tissues a
radiological assessment of the marginal bone level around the
shoulder of an implant is a reliable option
Grusovin et al 2008
11. • To consider an implant as successful, it has to meet criteria
with respect to tissue physiology (osseointegration), function
(mastication), absence of pain and user satisfaction
Tonetti & Palmer 2012
• In 1986, Albrektsson et al stated that a mean marginal bone
loss of 1.5 mm after the first year of loading is acceptable.
12. • More recent studies show a mean marginal bone loss of 1.0
mm after the first year of loading and in the following years
an annual 0.1 mm additional bone loss
Cecchinato et al 2008
• Some papers indicate that the bone thickness around an
implant should be at least 1 or 2 mm to assure long-term
success and bone coverage
Esposito et al 2007, Grunder et al 2005
13. Aim
• This prospective follow-up study aims to evaluate the
radiological interproximal bone changes of oral implants
placed in sites with ≤ 4.5 mm of bucco-oral bone width.
14. Material and Methods
• This prospective, single-centre study was carried out at the
Department of Periodontology of the University Hospitals
Leuven.
• All oral implants (Astra Tech, Dentsply Implants, M€olndal,
Sweden) were placed in the period between 2009 and 2010.
15. Inclusion criteria
• Implant sites with ≤4.5 mm bone in bucco-oral dimensions, as
measured on CBCT cross-sectional images (2-mm subcrestally)
• Only those patients, with a very limited bucco-oral dimension
over the crest were included.
• Patients expectations were pure functional, without any
severe aesthetical demand.
16. • All implant sites were analysed on a multi-slice CT (Somatom
Plus S, Siemens, Erlangen, Germany) or cone-beam CT
(Scanora 3D, Soredex, Tuusula, Finland).
• The implants were placed according to the surgical protocol
provided by the implant company (Instruction manual, Astra
Tech, DentsplyImplants, M€olndal, Sweden).
• However, in most cases, the surgical protocol was changed
accordingly to the situation.
17. • The amount of buccal bone on the implant was <1 mm at
each implant site.
• Whenever a fenestration or dehiscence occurred, a GBR
procedure was performed.
• A thin layer of “deproteinized bovine bone matrix” (Bio-
OssTM, Geistlich, Switzerland) was used and covered with a
resorbable collagen membrane (Bio-GideTM, Geistlich,
Switzerland).
• The digital intra-oral radiographs (follow-up) were obtained
18. Marginal bone level changes
• The intra-oral, long-cone radiographs were taken at: implant
placement, functional loading, 1, 2 and 3-years follow-up.
• The distances, in millimetres, between the shoulder of the
implant and the first clear bone-to-implant contact were
recorded both mesially and distally.
• The thread pitch distance and the full length of the implant
were also recorded.
19. • These measurements (accuracy of 0.01 mm) were performed
with a software program (IMAGE J, NIH, Bethesda, Maryland,
USA).
• The measurements were initially made in a pixel format.
• Linear distance measurement (mm) could be retrieved after
calibration of the images according to the respective thread
pitch distance, provided by the manufacturer.
• The full length of the implant was used for the conversion.
20. Width of the alveolar process
• The width of the alveolar process on the future implant
osteotomy sites was measured, pre-operatively, on cross-
sectional images of the conebeam
• CT or multi-slice CT, using the software tool to the nearest 0.1
mm (PACS lightbox, IMPAX pacs, Agfa).
• Measurements were made at the top of the crest and at every
2 mm (2, 4, 6, 8, 10 and 12 mm below the first measurement).
21. Clinical case with intra-oral radiographs
showing the bone level after 3 years of loading.
22. Results- Patient and implant data
• A total of 28 patients (three males and 25 females) were
included.
• A total of 100 implants were placed (13 in males, 87 in
females). Two in one patient with diabetes and seven in two
patients with a history of radiotherapy outside the head and
neck region.
23. • Eighty-eight per cent of the implants were placed in the upper
jaw and 12% in the lower jaw, primarily in the region between
the 2nd incisor and 2nd premolar.
24. • All implants had a diameter of 3.5 mm and their length ranged
from 8 mm to 15 mm.
• The majority of the implants had a length of 13 mm (45%) or
11 mm (33%). The mean width of the future osteotomy at the
top of the crest was 2.8 mm (SD: 0.8;range [1.1; 4.4]).
25. • None of the implants were placed in extraction sockets.
• The mean submerged healing period was 3.6±0.9 months.
26. Marginal bone level changes
• The implants were primarily placed subcrestally (mesially:
0.94 mm±0.87, and distally: 0.68 mm±0.97 below bone level).
• At abutment connection the marginal bone was located 0.65
±0.6 mm apically of the implant shoulder (mesially 0.63 ±0.7
mm, distally 0.67 ±0.6).
• One, 2 and 3 years after final abutment connection, this
“bone level” was slightly more apically (0.80, 0.84 and 0.79
mm apically to the implant shoulder, respectively).
28. Discussion
• The results of this prospective clinical follow-up study
demonstrated that the interproximal bone changes for
implants placed in sites with ≤ 4.5 mm of bucco-oral bone
width were stable during the 3 years of functional loading.
• Furthermore, the implant survival rate was 100%.
• The marginal bone changes around implants are most
common, between abutment connection and the first year of
functional loading.
29. • The present study showed a mean marginal bone loss of 0.17
mm ±0.40 in the first year of functional loading.
• After the first year the marginal bone loss varied a bit with
after 2 years a marginal bone loss increase with another 0.05
mm ±0.37 and after 3 years a marginal bone loss decrease
with 0.06 mm ±0.14.
30. • The bucco-oral bone width is considered to be crucial for
osseointegration and even more important for an aesthetic
outcome.
• In the literature there are some guidelines available which
suggested a zone of 1.5–2 mm of bone around the implant
Esposito et al 2007, Grunder et al 2005
31. • Small-diameter implants have become a popular treatment
option to avoid bone augmentation procedures and more
complex surgery.
• In some studies, implants with a width of 3.5 mm are
considered small diameter implants
Sohrabi et al 2012
• Other studies consider small diameter implants as those with
a width ≤3.3 mm
Ortega-Oller et al 2014
32. • A recent (systematic/narrative) reviews concluded that the
survival rates small-diameter implants are similar to those
reported for standard width implants
Hasan et al 2014, Sohrabi et al 2012
• The present study indicates that bone grafting procedures can
be avoided when sites with ≤4.5 mm of bucco-oral bone width
are available.
33. • All patients included in the study, were following a very strict
maintenance protocol and as a result had a high level of oral
hygiene.
• This might not be the best reflection of an average patient in
the daily practice.
34. Conclusion
• Within the limits of this study, it can be concluded that
implants placed in sites with limited dimensions (≤4.5 mm
vestibule-oral) can be successful for a period of 3 years,
comparable to implants placed in wider alveolar crests.
• This effect could be explained by the microthreads in the
conical and marginal part of the implant system used as well
as by the special drilling sequence avoiding bone
compression.
• These results showed that if patients are not ready for bone
grafting procedures this treatment option could be a good
alternative.
36. I. Survival rates of short (6 mm) micro-rough surface
implants: a review of literature and meta-analysis
Srinivasan M et al , Clin Oral Implants Res 2014
OBJECTIVE:
• The aim of this review was to test the hypothesis that 6 mm
micro-rough short Straumann implants provide predictable
survival rates and verify that most failures occurring are early
failures.
MATERIALS AND METHODS:
• A PubMed and hand search was performed to identify studies
involving micro-rough 6-mm-short implants published
between January 1987 and August 2011. Studies were
included that (i) involve Straumann(®) 6 mm implants placed
in the human jaws, (ii) provide data on the survival rate, (iii)
mention the time of failure, and (iv) report a minimum follow-
up period of 12 months following placement.
37. RESULTS:
• From a total of 842 publications that were screened, 12
methodologically sound articles qualified to be included for
the statistical evaluation based on our inclusion criteria.
CONCLUSION:
• This meta-analysis provides robust evidence that micro-rough
6-mm-short dental implants are a predictable treatment
option, providing favorable survival rates. The failures
encountered with 6-mm-short implants were predominantly
early and their survival in the mandible was slightly superior.
38. II. Failure rates of short (≤ 10 mm) dental implants and
factors influencing their failure: a systematic review
Sun HL , Int J Oral Maxillofac Implants.2011
PURPOSE:
• The aim of this study was to evaluate the long-term failure
rates of short dental implants (≤ 10 mm) and to analyze the
influence of various factors on implant failure.
MATERIALS AND METHODS:
• The PubMed and Cochrane Library databases were consulted
for follow-up studies published between the years 1980 and
2009. For those studies that met the inclusion and exclusion
criteria, data concerning the number of implants (≤ 10 mm)
placed and lost and any related risk factors were gathered in
tables and subjected to analysis. Univariate and multivariate
analyses were performed.
39. RESULTS:
• The heterogeneity and low quality of the included studies made
meta-analysis impossible. A total of 35 human studies fulfilled the
criteria. There was a tendency toward higher failure rates for the
maxilla and for dental implants with a machined surface compared
with the mandible.
CONCLUSIONS:
• Among the risk factors examined, most failures of short implants
can be attributed to poor bone quality in the maxilla and a
machined surface. Although short implants in atrophied jaws can
achieve similar long-term prognoses as standard dental implants
with a reasonable prosthetic design according to this review,
stronger evidence is essential to confirm this finding.
Notes de l'éditeur
BODY It is placed within the bone during the first stage of surgery It is made up of commercially pure titanium or titanium alloy
COVER SCREW It is placed on superior surface of body of implant to prevent growth of tissues over the edges of implants
Abutment
It is part of implant which resembles prepared tooth & is designed to be screwed into the implant body It provides retention for the prosthesis
(fixed partial denture)
Transfer coping
It is used to facilitate the transfer of intraoral location of implants to a similar position on the casT
Laboratory Analogue
Counter part of the implant assembly in the cast on which abutment is attached to prepare a crown
This permits enough space for occlusal material strength & aesthetics, abutment height retention and hygiene considerations.
Removable prosthesis often require 12mm or more of interarch space for denture teeth & acrylic base strength, attachments, bars & hygiene considerations.
Thread pitch- defined as the distance between two neighboring threads measured on the same side of the axis, also ref to no of threads per unit, smaller pitch indicate more thread leading to more surface area,